S33E-01
Uncovering the geodetic signature of silent slip through repeating earthquakes
Wednesday, 16 December 2015: 13:40
305 (Moscone South)
William Frank1, Mathilde Radiguet2, Baptiste Rousset2, Nikolai Shapiro3, Allen L Husker4, Vladimir Kostoglodov4, Nathalie Cotte2 and Michel Campillo2, (1)Institut de Physique du Globe de Paris, Paris, France, (2)ISTerre Institute of Earth Sciences, Saint Martin d'Hères, France, (3)Institut de Physique du Globe de Paris, Paris Sorbonne Cité, CNRS, Paris, France, (4)U.N.A.M., Mexico City, Mexico
Abstract:
Slow transient slip that releases stress along the deep roots of plate interfaces is most often observed on regional GPS networks installed at the surface. The detection of slow slip is not trivial if the dislocation along the fault at depth does not generate a geodetic signal greater than the observational noise level. Instead of the typical workflow of comparing independently gathered seismic and geodetic observations to study slow slip, we use repeating low-frequency earthquakes to reveal a previously unobserved slow slip event. By aligning GPS time series with episodes of low-frequency earthquake activity and stacking, we identify a repeating transient slip event that generates a displacement at the surface that is hidden under noise prior to stacking. Our results suggest that the geodetic investigation of transient slip guided by seismological information is essential in exploring the spectrum of fault slip.
